JPH0349363Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a positive temperature coefficient thermistor device used in an electronic mosquito repellent etc. By providing a reinforcing part that protrudes from one side to the other, the mechanical strength of the lead-out terminal part can be increased while maintaining a thin plate suitable for forming an overcurrent fusion part. In addition, it is possible to suppress floating or rattling of the lead-out terminal portion in the terminal lead-out path, and to prevent mechanical deterioration of the narrow width portion, fluctuation of the overcurrent blowout value, etc.

<Prior art> In this type of PTC thermistor device, when the PTC thermistor deteriorates, an overcurrent flows during thermal equilibrium when the current should normally be low, causing damage to the PTC thermistor, abnormal heat generation, and accompanying fire. This could lead to an extremely dangerous situation. Therefore, a positive temperature coefficient thermistor device has been proposed in which an electrode terminal is provided with a narrow portion that serves as an overcurrent fusing portion. For example, Utsukai Showa 52
- In Publication No. 171738, the bent part of the lead-out terminal part of the electrode terminal plate is narrowed to form an overcurrent fusing part, and the positive temperature coefficient thermistor is protected by fusing the overcurrent fusing part when an overcurrent flows. are doing.

However, in a structure in which the bent part of the outgoing terminal part is narrowed to form an overcurrent fusing part, the strength of the outgoing terminal part is significantly reduced at the overcurrent fusing part, so the outgoing terminal part is easily damaged. Resulting in. If the cross-sectional area of the bent portion is increased, the mechanical strength will increase, but the fusing current level will increase, resulting in a decrease in the overcurrent protection function. Moreover, since the bent part is dimensionally short and there are limitations from the mechanical strength perspective as mentioned above, the degree of freedom in designing the overcurrent fusion part is low, and the design width of the overcurrent value to be protected is low. becomes narrower.

5 and 6 show a conventional example capable of solving the above-mentioned problems, in which an elastic electrode terminal 3 is arranged in a groove 2 of a case 1 made of a heat-resistant insulating material such as alumina, and the elastic electrode terminal 3 is A positive temperature coefficient thermistor 4 having electrodes 41 and 42 adhered to both sides in the thickness direction, an electrode terminal 5, and a heat-resistant insulating plate 6 made of mica or the like are sequentially stacked on top of the insulating plate 6. The heat dissipation plate 7 is pressed in the direction of the case 1 while resisting the elastic force of the elastic electrode terminal 3, and the mounting arms 71 to 74 provided on the heat dissipation plate 7 are bent along the outer wall of the case 1. As a result, the entire structure is elastically supported and fixed. The heat dissipation plate 7 is a portion that serves as a medicine stand, and is formed of a stainless steel plate material or the like.

The elastic electrode terminal 3 has an elastic electrode contacting part 31 that is in pressure contact with the electrode 41 of the positive temperature coefficient thermistor 4, and a thin plate-shaped lead-out terminal part 32 extending from the electrode-facing part 31. 32 is led out from the bottom through a hole 102 formed in the case 1.

The electrode terminal 5 is composed of a single metal thin plate, and has an electrode contacting part 51 that contacts the electrode 42 of the PTC thermistor 4 and a lead-out terminal part 52 spaced apart from each other on the side of the electrode contacting part 51. It has a structure in which it is made continuous by a formed narrow width part 53, and this narrow width part 53 is used as an overcurrent fusing part. The pull-out terminal portion 52 is the narrow width portion 5
3, and is led out from the bottom of the case 1 through a terminal lead-out path 101 formed by a hole or the like formed from the open end side of the case 1 to the opposite side.

The narrow width portions 53 are arranged side by side at intervals on the side of the electrode contact portion 51, and one end thereof is connected to the electrode contact portion 51.
Since the other end is connected to the lead terminal part 52, the length of the narrow part 53 which becomes the overcurrent fusing part is d ₁
However, it is not limited by the length of the lead-out terminal portion 52. Therefore, the degree of freedom in selecting the length of the narrow portion 53 is increased, and the fusing current value can be easily set.

The electrode terminals 3 and 5 are manufactured by using, for example, a stainless steel plate or the like and punching it into a predetermined pattern. Among the electrode terminals 3 and 5, the electrode terminal 5 has a narrow portion 5 that becomes an overcurrent fusing portion.
Ideally, the plate thickness of No. 3 should be a thin plate that can be quickly fused at a small current level, and the pull-out terminal portion 52, which is led out to the outside and becomes a connection part, should be made thicker to increase mechanical strength. It is technically difficult to make the two plates different in thickness since they are manufactured by punching from the same plate material. If the plate thickness is adjusted to the thickness required for the lead-out terminal portion 52, the time and current required for overcurrent fusing at the narrow width portion 53 will become too large, making it impossible to obtain an appropriate overcurrent protection effect. Therefore, the narrow portion 53
The overall thickness of the plate is determined according to the thin plate thickness required.

<Problems to be solved by the invention> As mentioned above, in this type of positive temperature coefficient thermistor device, ensuring appropriate overcurrent protection is the first priority, and the plate thickness of the electrode terminal 5 is adjusted to prevent overcurrent fusing. Since the plate thickness was set to be as thin as required for the narrow width part 53, the plate thickness of the lead-out terminal part 52 was significantly less than the actually required value, and the necessary mechanical strength could not be secured, making it easy to There were problems such as bending.

Furthermore, since the case 1 is generally made of a molded product such as alumina, the diameter of the terminal lead-out path 101 through which the lead-out terminal portion 52 of the electrode terminal 5 passes is set to 1 mm or less due to its moldability. difficult to do. On the other hand, the electrode terminal 5 is made of a thin stainless steel plate having a thin plate thickness required for the narrow portion 53, for example, about 0.1 mm. Therefore, between the terminal lead-out path 101 and the lead-out terminal portion 52 of the electrode terminal 5,
A gap of 0.9 mm, which is nine times the thickness of the pull-out terminal portion 52, is generated, and the pull-out terminal portion 52 is connected to the terminal lead-out path 1.
Floating within 01. Since the lead terminal part 52 is connected to the narrow part 53 which becomes the overcurrent fusing part, floating of the lead terminal part 52 is transmitted to the narrow part 53, stress is applied to the narrow part 53, and mechanical strength is deteriorated. , causing undesirable effects such as fluctuations in overcurrent fusing values.

Therefore, the object of the present invention is to solve the above-mentioned problems, provide a wide selection range of fusing current values, and increase the mechanical strength of the lead-out terminal, while preventing floating, rattling, etc. of the lead-out terminal. It is an object of the present invention to provide a positive temperature coefficient thermistor device with high reliability.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention provides an elastic electrode terminal, a positive temperature coefficient thermistor having electrodes on both sides in the thickness direction, and an overcurrent melting device in a groove provided in the case. A positive temperature coefficient thermistor device in which an electrode terminal having an overcurrent fusing part, an electrical insulating plate, and a heat sink are sequentially stacked in this order, the electrode terminal having an overcurrent fusing part having a
It is composed of a thin metal plate and has an electrode contacting part, a narrow part serving as an overcurrent fusing part, and a lead-out terminal part, and the electrode contacting part is connected to the electrode of the PTC thermistor. The narrow width portions have planar portions that are in surface contact with each other, and the narrow width portions are arranged side by side at intervals on the side of the electrode contact portion, one end of which is connected to the electrode contact portion, and the other end of which is connected to the lead-out terminal portion. The lead-out terminal portion is led out from an open end surface side of the case to the other end surface side through a terminal lead-out path provided in the case, and has at least a portion located within the terminal lead-out path on one side. It is characterized by having a reinforcing portion formed to be concave and protrude to the other surface side.

<Function> The narrow portions are arranged side by side at intervals from the electrode contact portion, and one end is connected to the electrode contact portion and the other end is connected to the lead-out terminal portion, so that overcurrent fusing is avoided. The length of the narrow width portion serving as the portion is not limited by the length of the lead-out terminal portion. The length can be set to at least correspond to the width or length of the electrode contact portion. Therefore, the degree of freedom in selecting the length of the narrow portion is increased, and the fusing current value setting range is expanded.

The lead-out terminal portion is led out from the open end surface side of the case to the other end surface side through a terminal lead-out path provided in the case, and has one surface side recessed and protrudes to the other surface side at least in a portion located within the terminal lead-out path. Since the reinforcing portion is formed in this manner, the mechanical strength of the lead-out terminal portion can be improved while maintaining the thin plate thickness required for the narrow width portion forming the overcurrent fusing portion.

Since the reinforcing portion is formed at least in the portion located within the terminal lead-out path, the gap between the terminal lead-out path and the pull-out terminal portion is reduced, and floating and backlash of the pull-out terminal portion within the terminal lead-out path are prevented. suppressed. For this reason,
Deterioration of the mechanical strength of the narrow width portion due to floating or looseness of the lead-out terminal portion in the terminal lead-out path, fluctuation of the overcurrent blowout value, etc. are prevented.

<Example> Fig. 1 is an exploded perspective view of a PTC thermistor device according to the present invention, Fig. 2 is an enlarged exploded perspective view of a partially assembled state, Fig. 3 is an assembled sectional view thereof, and Fig. 4 is a sectional view taken along the line _A1 - _A1 in FIG. 3. In the figure, the same reference numerals as in FIGS. 5 and 6 indicate the same components. The narrow part 53 that becomes the overcurrent fusion part is the electrode contact part 51
are arranged side by side at intervals, one end is connected to the electrode contact part 51, and the other end is connected to the lead-out terminal part 52.
It is connected to the. With such a structure, the length of the narrow portion 53 serving as the overcurrent fusing portion is not limited by the length of the lead terminal portion 52. The length can be set to at least correspond to the width or length of the electrode contact portion 51. Therefore, the degree of freedom in selecting the length of the narrow portion 53 is increased, and the fusing current value setting range is expanded.

The lead-out terminal portion 52 is led out from the open end surface side of the case 1 to the other end surface side through the terminal lead-out path 101 provided in the case 1, and is led out from the open end surface side of the case 1 to the other end surface side through the terminal lead-out path 101 provided in the case 1.
1, a convex reinforcing portion 52 formed so as to concave one side and protrude to the other side.
1. Such a reinforcing portion 521 can be formed, for example, by press working. The electrode terminal 5 is made of SUS-304 with a thin plate thickness required for the narrow width portion 53, for example, about 0.1 mm, and is punched into a predetermined pattern and subjected to necessary bending, plastic processing, etc. The electrode contact portion 51, the lead-out terminal portion 52, and the narrow width portion 53 have the same plate thickness. Therefore, the mechanical strength of the lead-out terminal portion 52 can be increased by increasing the mechanical strength of the lead-out terminal portion 52 while maintaining a thin plate thickness suitable for overcurrent fusing required in the narrow portion 53.
21 can be improved.

The reinforcing portion 521 at least connects the terminal lead-out path 101
Since it is provided in the inner portion, the gap between the terminal lead-out path 101 and the pull-out terminal portion 52 is reduced, and floating and rattling of the draw-out terminal portion 52 within the terminal lead-out path 101 is suppressed. Therefore, the terminal lead-out path 1
This prevents deterioration of the mechanical strength of the narrow width portion 53 due to floating or looseness of the lead-out terminal portion 52 within the 01, and fluctuations in the overcurrent blowout value. In this embodiment, a similar convex reinforcing portion 3 is also provided on the lead-out terminal portion 32 of the electrode terminal 3.
21 is formed.

103 is a recess formed on the open end surface 104 of the case 1 in which the groove 2 is opened. This recess 1
03 is formed at a position corresponding to the narrow width portion 53 of the opening end surface 104 so as to be independent from the groove 2. In the assembled state, as shown in FIG. 4, the narrow portion 53 of the electrode terminal 5 is located within the recess 103;
The structure is such that the top thereof is closed with an insulating plate 6.

With such a structure, when the narrow portion 53 is fused due to an overcurrent, the molten metal remains within the recess 103 and does not scatter into the recess 2 where the positive temperature coefficient thermistor 4 is located. Therefore, the extraction terminal portion 52
Even if an electric circuit that bypasses the narrow portion 53 is formed between the electrode contact portion 51 and the electrode contact portion 51, a short circuit between the electrodes 41 and 42 due to adhesion of molten metal to the outer circumferential surface of the positive temperature coefficient thermistor 4 may occur. can be prevented.

Further, the electrode terminal 5 is provided with a curved portion 531 that is recessed downward so as to be spaced from the insulating plate 6 stacked thereon, approximately in the middle of the narrow width portion 53, and this curved portion 531 is inserted into the recessed portion 103. It is located. With such a structure, the narrow portion 53 is separated from the insulating plate 6 by the amount of the recess at the curved portion 531, and the thermal coupling is reduced. Therefore, when an overcurrent flows, resistance heat generation in the curved portion 531 occurs. The temperature becomes higher, the curved portion 531 is reliably fused, and the fused time is also shortened.

Further, a bent piece 54 is provided around the electrode terminal 5, and this bent piece 54 is inserted and positioned in a recess 105 formed in the end surface 104 of the case 1. With such a structure, the narrow portion 53 is fused due to overcurrent, and the electrode contact portion 51 is connected to the lead-out terminal portion 5.
Even if it is separated from the electrode contact portion 5
1 does not move on the positive temperature coefficient thermistor 4. Therefore, it is possible to prevent the electrode contact portion 51 from electrically contacting the fused end portion of the extraction terminal portion 52 after the overcurrent fusion occurs.

Further, in this embodiment, a stepped portion 55 is formed above the lead-out terminal portion 52, and the stepped portion 55 is sandwiched between the end surface 104 of the case 1 and the insulating plate 6. With this structure, if an external force is applied to the pull-out terminal portion 52 in the assembled state, the external force will be applied to the narrow portion 5.
It is possible to prevent the narrow width portion 53, which has a weak mechanical strength, from being damaged by the external force applied to the pull-out terminal portion 52.

<Effects of the invention> As described above, according to the invention, the following effects can be obtained.

(a) The narrow portions are arranged side by side at intervals from the electrode contact part, and one end is connected to the electrode contact part and the other end is connected to the lead-out terminal part, so overcurrent fusing is prevented. It is possible to provide a positive temperature coefficient thermistor device that has a high degree of freedom in selecting the length of the narrow portion that serves as the section, and has a wide fusing current value setting range.

(b) The lead-out terminal portion is led out from the open end side of the case to the other end side through a terminal lead-out path provided in the case, and is recessed on one side and recessed on the other side at least in the portion located within the terminal lead-out path. Since the reinforced part is formed to protrude from the outside, it improves the mechanical strength of the lead terminal part and allows for low current levels while maintaining the thin plate thickness required for the narrow part that forms the overcurrent fusing part. It is possible to provide a highly reliable positive temperature coefficient thermistor device that can be quickly fused and has great mechanical strength.

(c) Since the reinforcing part is formed at least in the part located within the terminal lead-out path, the mechanical strength of the narrow part due to floating or looseness of the lead-out terminal part in the terminal lead-out path deteriorates, and the overcurrent fusion value is reduced. Therefore, it is possible to provide a positive temperature coefficient thermistor device that prevents fluctuations in .

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a PTC thermistor device according to the present invention, Fig. 2 is an enlarged exploded perspective view of a partially assembled state, Fig. 3 is an assembled sectional view thereof, and Fig. 4 is a Fig. 3 A sectional view on line A ₁ − A ₁ ,
FIG. 5 is an exploded perspective view of a conventional PTC thermistor device, and FIG. 6 is an assembled sectional view thereof. DESCRIPTION OF SYMBOLS 1... Case, 3... Elastic electrode terminal, 5... Electrode terminal, 4... Positive temperature coefficient thermistor, 6... Insulating plate, 7... Heat sink, 51... Electrode contact portion, 52...
...Output terminal part, 53...Narrow width part, 521...Reinforcement part.

Claims (1)

[Scope of claims for utility model registration] (1) In the groove provided in the case, the elastic electrode terminal and
A positive temperature coefficient thermistor device comprising a positive temperature coefficient thermistor having electrodes on both sides in the thickness direction, an electrode terminal having an overcurrent melting section, an electrical insulating plate, and a heat sink, which are stacked in this order in this order, The electrode terminal has a portion,
It is composed of a single thin metal plate and has an electrode contacting part, a narrow part serving as an overcurrent fusing part, and a lead-out terminal part, and the electrode contacting part is the electrode of the positive temperature coefficient thermistor. The narrow part has a flat part that makes surface contact with the electrode contact part, and the narrow part is arranged side by side at intervals on the side of the electrode contact part, one end is connected to the electrode contact part, and the other end is connected to the electrode contact part. The lead-out terminal part is led out from the opening end surface side of the case to the other end surface side through a terminal lead-out path provided in the case, and is connected to at least a portion located in the terminal lead-out path. A positive temperature coefficient thermistor device, characterized in that it has a reinforcing portion formed to be concave on one side and protrude to the other side. (2) A utility model registered as claimed in claim 1, characterized in that a recess defined from the groove is formed on the opening end surface of the case, and the narrow portion is located within the recess. positive characteristic thermistor device. (3) The positive temperature coefficient thermistor device according to claim 2, wherein the narrow portion has a curved portion that is recessed into the recessed portion. (4) The electrode terminal provided with the narrow width portion has a bent piece at the peripheral portion, and the bent piece is inserted and positioned in another recess formed in the opening end surface of the case. A positive temperature coefficient thermistor device according to claim 1, 2, or 3 of the patented utility model claim. (5) The electrode terminal provided with the narrow width portion has a stepped portion at a connecting portion between the lead-out terminal portion and the narrow width portion, and the stepped portion is connected to the end surface of the case and the insulating plate. A positive temperature coefficient thermistor device according to claim 1, 2, 3, or 4 of the utility model registration claim, characterized in that the positive temperature coefficient thermistor device is sandwiched between.